DIRECTIONAL WAVE EFFECTS ON LARGE OFFSHORE STRUCTURES

Linear diffraction theory for large floating offshore structures of arbitrary shape and subjected to a regular uni‐directional wave train is extended to obtain the forces and responses in multi‐directional random waves with a specified directional wave spectrum. The transfer functions, spectra and crossspectra of the components of forces and motions are first obtained. These are used in turn to obtain the probabilistic properties of the corresponding force and response components and their horizontal resultants. In particular, the expected values of the single largest maxima of these forces and responses in a specified duration are obtained.